During chemical processing, it may be desirable or necessary to analyze a stream such as a feed stream, process stream, or product stream, to determine its composition and to determine whether chemical process conditions are optimal. Such process analysis typically involves collecting a sample from a selected stream in a sampling cylinder and analyzing the sample outside of the processing unit.
Analysis of certain chemicals, such as light end hydrocarbons, may require collection of a sample including a liquid portion and a vapor portion. In certain circumstances, the analytical method may require a liquid and vapor portion for accuracy. Additionally or alternatively, the analytical method may require a liquid and vapor portion for purposes of safety. For example, the vapor portion may provide a safety margin to mitigate concerns of sampling cylinder rupture caused by thermal expansion in a liquid-filled sampling cylinder.
To verify that a sample includes a liquid and vapor portion, conventional sampling cylinders are typically used with pipes or tubes having transparent windows or sight glasses. For such a conventional sampling cylinder used with pipes or tubes having transparent windows, a collected sample may be optically inspected to verify the presence of a vapor portion, such as by locating a vapor-liquid phase boundary. However, sight glasses are not appropriate for use with certain chemicals. For example, alkylation processes using hydrofluoric (HF) acid may require process analysis. Streams under analysis in such HF alkylation processes may chemically attack the sight glass used with a sampling cylinder. As a result, the sight glass may be structurally compromised and undesirable leakage of process streams may occur. To ensure safety, use of sight glasses may be completely banned around such processing units.
Accordingly, it is desirable to provide improved methods, apparatuses, and kits for collecting chemical samples. It is also desirable to provide methods, apparatuses, and kits for collecting chemical samples that ensure collection of a sample with a liquid portion and a vapor portion. Also, it is desirable to provide such methods, apparatuses, and kits for collecting chemical samples that avoid use of sight glasses or windows. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.